The present invention relates to a testing device and testing method for carrying out a high voltage testing of a device to be tested.
A testing method exists whereby a high voltage test is supplied to a device to be tested, and a high voltage testing of the device is carried out. With this kind of testing method, a dielectric breakdown and a discharge occurs between electrodes of the device to be tested, or between electrodes of the device to be tested and a testing device, and the like. There is a possibility of the device to be tested or testing device being damaged, and a possibility of the testing of the device to be tested not being carried out correctly.
For this reason, a technology exists whereby the device to be tested is disposed in an environment of a gas with a high insulation property, for example, sulfur hexafluoride gas (SF6), and high voltage testing is performed after ensuring the dielectric strength of the testing environment.
However, a gas with a high insulation property, typified by sulfur hexafluoride gas, has a high global warming potential (GWP), and the burden on the global environment is large. For example, the global warming potential of sulfur hexafluoride gas is “23,900”.
For this reason, consideration is given to suppressing discharge with a method other than the method using a gas with a high insulation performance. For example, there is a technology whereby an insulation shield is disposed in a discharge path. For example, a high voltage testing device exists that has an insulation shield that comes into contact with the surface of a seal between first and second leads of a subject of measurement (for example, refer to JP-A-11-271387). Also, a semiconductor wafer measuring device exists wherein an insulation member is interposed between the leading ends of a pair of probes that comes into contact with a wafer, in such away as to come into contact with the wafer (for example, refer to JP-A-2010-10306).
Also, as another method, there is a technology whereby testing is carried out in a condition in which a device to be tested is immersed in an insulating solution. For example, a technology exists whereby withstand voltage measurement is performed with a semiconductor device immersed in a fluorocarbon solution with an insulation property (for example, refer to JP-A-6-120315). Also, a technology exists whereby the withstand voltage of a semiconductor substrate is inspected by covering at least the surface of the semiconductor substrate with an insulating solution, and applying a voltage between at least two places on the semiconductor substrate (for example, refer to JP-A-2003-100819).
However, with the method whereby an insulation shield is disposed in the discharge path, a structure wherein the insulation shield is disposed in a predetermined position is necessary, meaning that there is a possibility of the testing device becoming complicated.
Also, with the method whereby testing is carried out in a condition in which the device to be tested is immersed in an insulating solution, since the insulating solution is used, there is a possibility that the equipment for the testing becomes complicated. For example, when a solution with a low boiling point, such as fluorocarbon, is used as the insulating solution, an equipment for preventing the insulating solution from evaporating during the testing, or equipment for the evacuation or collection of gas when drying, is necessary. Also, even when a solution that does not have a low boiling point is used as the insulating solution, equipment for cleaning is necessary.